156 MEO Le URSiCRAe 
lemon-yellow, or tinted bronze at the centre; head short and broad, 
lobed in front; tentacles very short, scarcely longer than the head, 
bluish; eye pedicles about one-third the length of the tentacles, large, 
yellow ; mantle dirty green. 
Figures 177, 177 a, lateral and basal view of the animal, with the 
shell. 
NAVICELLA PORCELLANA (Cuemnitz), N. elliptica, Lamarck, Dr- 
SHAYES, Rectuz, &c. 
Anima above slaty, with lilac tints, slightly lineated with dusky 
along the sides; foot grayish, with lilac reflections ; tentacles long and 
tapering, olivaceous. 
Figures 178, 1784, lateral and basal views of the animal, with the 
shell. 
NERITINA CHOLERICA. 
Testa obliqué semiglobulosa, solidula, leviter striata, castaneo-fusca, sub- 
tus interdum lineolis flecuosis nigris picta: spira viz exserta, ultimo 
anfractu recurrente fere tnvoluta: apertura oblique semicircularis, 
magna, postice canaliculata ; labro flavo ; labio planulato extrinsecus 
sanguineo tincto ; columella alba, valde sinuata, denticulata. Oper- 
culum tenue, lividum, sulco divisum, granulatum, ad apicem flavi- 
dum. 
Neritina cholerica, GouLp ; Proceed. Boston Soc. Nat. Hist., 11. 237. 
July 1847. Expedition Shells, 47. 
ANIMAL with a large cream-coloured foot, shaded olive beneath ; 
mantle dark olive ; head short and broad, above pale yellow, concentri- 
cally striated with coarse, interrupted, dark olive lines; tentacles very 
slender ; eye pedicles stout, long, whitish. 
SHELL rather large, semi-globose, a little oblique, with pretty dis- 
